JPH05171079A - Ink and ink jet printer - Google Patents

Abstract

PURPOSE:To obtain an ink for an ink jet printer having excellent infrared absorptivity, not undergoing chemical change even when repeatedly exposed to high temperatures and being difficultly foamable by using a compound having a specified molecular structure as an ink material. CONSTITUTION:This ink contains a compound of the formula [ wherein R is O, S, Se, Te or (-CH3)2; R2 is CnH2n+1 (wherein n=1-4); and R3 is ClO4<-> or I<->]. This ink is combined with each of an ink jet printer in which thermal energy is used as the energy for ink delivery and an ink jet printer in which energy generated by electromechanical transduction is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel ink and ink jet printer, and more particularly to an ink jet recording system in which ink is ejected from a fine ejection port (nozzle hole) provided in a recording head and recording is performed by the droplets. Suitable for
The present invention relates to an ink composition having infrared absorption characteristics and an inkjet printer using this ink.

[0002]

2. Description of the Related Art Optical character recognition scanning devices (OCR, OMR), which have been used in ATMs and the like that can be used to enter passbooks, and recently used in various fields such as physical distribution management and product management. The bar code type scanning device that has come to be used is a 632.8 nm He-Ne laser,
Since 660 nm light-emitting diode, 670 nm semiconductor laser, 690 nm light-emitting diode, 780 nm semiconductor laser, 940 nm infrared light-emitting diode, etc. are used as the light source, the printers for these scanning devices use red light or near red light. A dot-type printer using a pigment such as carbon black, which is sensitive to external light, as a colorant has been used. However, the dot type printer has a problem that the printing sound is loud. Further, if there is a step on the recording medium, there is a problem that the wire pin of the recording head is caught at the step and pin breakage occurs or pin wear is accelerated, and the reliability of the recording head and the printer is impaired.

Therefore, in recent years, an inkjet recording ink containing a specific dye that absorbs infrared light and an inkjet printer using the same have been actively developed. For example, a method in which a chromium complex salt dye and a specific polar substance are combined (JP-A-56-135568), a method in which a specific dye such as sulfa black 1 and an anticoagulant are combined (JP-A-57-14660), and the like have been proposed. ing. These methods not only have the property of absorbing infrared light, but also have storage stability as an ink so that the physical properties of the ink do not change during long-term storage and solids do not precipitate. Is also noted.

However, the ink used in the ink jet printer is required to satisfy the following conditions in addition to the above characteristics in order to obtain good recording.

(1) Physical properties such as viscosity, surface tension, electrolysis, density, etc. are within proper ranges according to the ink ejection characteristics of the recording head.

(2) During long-term use, solid content is deposited due to a chemical change between the material of the recording head or a part that holds the ink and the ink, or a chemical change due to heat acting on the ink. It does not occur or the physical properties of the ink do not change.

(3) The nozzle hole of the recording head of an ink jet printer generally has a diameter of about 10 to 80 μm, and if the nozzle hole is clogged, or even if it is not completely clogged, solids and sticky substances adhere to the vicinity of the nozzle. Or, if the physical property value of the ink in the nozzle, especially the viscosity changes greatly, the recording property, ejection stability, and ejection responsiveness deteriorate. Therefore, the nozzle holes of the recording head do not become clogged and the ink in the nozzle holes does not thicken during recording pause.

(4) A print density required for recording can be obtained.

Generally, when an attempt is made to increase the print density by increasing the dye content in the ink, the above-mentioned (3) clogging of the nozzle holes tends to occur. Therefore, a dye having a high solubility in a solvent used for ink and a high extinction coefficient (ability to absorb light of a certain wavelength) is required.

(5) The ink is quickly fixed on the recording material, and the dots do not have irregular bleeding.

(6) The recorded image has water resistance, light resistance, and scratch resistance.

Further, thermal energy corresponding to the recording signal is applied to the ink in the recording head, and the energy is ejected and ejected as droplets from the nozzle holes of the recording head to form flying droplets, and a dot image is formed on the recording medium. In an inkjet printer for recording, it is necessary to improve the repeated service life (durability life) of the recording head in order to improve the service life of the apparatus.

In the recording head as described above, a thermal head used in a facsimile or the like is formed in the ink flow path in the recording head, and the thermal head is caused to generate heat in response to a recording signal, thereby causing bubbles in the ink. It is generated and droplets are ejected and ejected at this pressure. For this reason, factors that determine the service life of the recording head applied to the recording method as described above include not only the life of the thermal head provided but also the deposition of solid matter on the surface thereof. That is, since the ink receives high heat when the generation and disappearance of bubbles are repeated, the thermally unstable ink causes a chemical change and deposits solid matter, which hinders the recording operation.

Actually, when the generation and disappearance of bubbles are continued for a long time, as a result, insoluble matter is generated and deposited near the surface of the thermal head, which makes it difficult for the thermal head to generate heat, and the recording head cannot be ejected. What happens is experienced and observed in many experiments.

Further, by applying pressure to the ink using the electromechanical conversion means, the ink is ejected and ejected as droplets from the nozzle holes of the recording head to form flying droplets, and an ink jet for recording a dot image on the recording medium. In the printer, in order to improve the reliability of the device, it is necessary to use an ink that hardly foams.

In this recording head, a voltage is applied to a piezoelectric element, which is an electromechanical converting means, which is adhered to a position called a pressure chamber in an ink flow path in the recording head, whereby the piezoelectric element is bent and pressure is applied. The volume of the chamber is reduced and ink droplets are ejected and ejected. However, if gas (air bubbles) is present in the ink flow path of the recording head in addition to the ink, even if the volume of the pressure chamber is reduced, the volume of the air bubbles contained therein is reduced, and The drops will not be ejected.
Here, it is considered that the reason why the bubbles infiltrate into the ink flow path is that the ink that easily foams is rapidly flown.

Actually, when the ink which is difficult to bubble is used, bubbles are not generated or the ejection failure is not generated in the ink flow path. However, when the ink which easily foams is used, the ink flow It has been experienced and observed in many experiments that the recording head cannot be ejected even if air bubbles are generated in the passage and therefore the piezoelectric element is bent and the volume of the pressure chamber is reduced.

[0018]

However, the above-mentioned conventional technique has the following drawbacks.

(1) When the ink of JP-A-56-135568 is used in an ink jet printer which generates droplets by applying thermal energy to the ink in the recording head, the ink is ejected and ejected tens of thousands of times. However, solid matter was found to be attached to the surface of the thermal head, and when the ejection and ejection of droplets were continued for tens of thousands of times, the recording head was unable to eject. When this ink was used in an ink jet printer that generates droplets by applying pressure to the ink using electromechanical conversion means, the printer that was printing before leaving was left at room temperature for 2 to 3 days. After that, when I tried to print, it became impossible to print.
When the nozzle hole of the recording head of the printer was observed with a microscope, solid matter was found to be deposited in the nozzle hole.

(2) When the ink of JP-A-57-14660 was used in an ink jet printer which generates droplets by applying pressure to the ink using electromechanical conversion means, ejection failure of the head occurred. When the ink flow path in the recording head was observed with a magnifying glass, a large amount of air bubbles having a diameter of about 0.1 mm were present.

(3) In the prior arts other than the above-mentioned two cases, inks have been developed to individually satisfy the required performances, but by combining them, all or a plurality of required performances are simultaneously satisfied. The ink to make it has not been developed yet.

Therefore, the present invention has been made in order to solve such a drawback as a result of years of earnest research by the authors, and not only is it excellent in infrared absorption but also the above-mentioned. Satisfy all required characteristics (1) to (6).

Furthermore, a characteristic characteristic of an ink jet printer that generates droplets by applying thermal energy to the ink in the recording head is that it undergoes a chemical change even when repeatedly exposed to high temperatures, and solids are formed on the surface of the thermal head. Things do not settle.

Further, it is difficult to foam, which is a required characteristic peculiar to an ink jet printer which generates droplets by applying pressure to ink using electromechanical conversion means.

It is an object of the present invention to provide an ink that satisfies all of these and an ink jet printer that uses this ink.

[0026]

The ink of the present invention is characterized by containing a compound represented by the general formula of Chemical formula 2 as an ink material for forming a recorded image.

[0027]

[Chemical 2]

(In the formula, R1 is O, S, Se, T
e, (-CH₃)₂R2 is C _nH_{2n + 1}(n = 1
~ 4), R3 is CIO_Four ^-, I^-Indicates any of the above. ) In addition, the ink jet printer of the present invention has
Applying energy to the droplets from the nozzle holes of the recording head
Are ejected and ejected to form flying droplets, which are then recorded on the recording medium.
In an inkjet printer that records dot images,
The ink contains a compound represented by the general formula
Characterize.

[0029]

[Chemical 3]

(In the formula, R1 is O, S, Se, T
e, (- CH _{3) 2} of either, R2 is _{C n H 2n + 1 (n} = 1
4), R3 represents either CIO ₄ ⁻ or I ⁻ . Further, the ink jet printer of the present invention applies pressure to the ink using the electromechanical conversion means, ejects and ejects as droplets from the nozzle holes of the recording head to form flying droplets, and forms a dot image on the recording medium. In the ink jet printer for recording, the ink contains a compound represented by the general formula (4).

[0031]

[Chemical 4]

(In the formula, R1 is O, S, Se, T
e, (- CH _{3) 2} of either, R2 is _{C n H 2n + 1 (n} = 1
4), R3 represents either CIO ₄ ⁻ or I ⁻ . )

[0033]

According to such means, since the components mixed in the ink have infrared absorbing properties, they can be applied to an optical character recognition scanning device or the like. In addition, since the chemical stability of the ink is high, it is suitable for printer ink.

[0034]

EXAMPLES The present invention will be described below based on examples.

The basic composition of the ink according to the embodiment of the present invention is firstly a colorant and secondly a solvent. Specific examples of the colorant include compounds having the following chemical structures. Two or more of these may be mixed and included in the ink.

[0036]

[Chemical 5]

[0037]

[Chemical 6]

[0038]

[Chemical 7]

[0039]

[Chemical 8]

[0040]

[Chemical 9]

[0041]

[Chemical 10]

[0042]

[Chemical 11]

[0043]

[Chemical 12]

[0044]

[Chemical 13]

[0045]

[Chemical 14]

[0046]

[Chemical 15]

If necessary, other oily dyes are added.

As the solvent, a mixture of various organic solvents is used as a main liquid medium component. As an organic solvent, it has a low vapor pressure and is difficult to evaporate and dry. Ethylene glycol, diethylene glycol, ethylene glycol monomethyl (ethyl,
Butyl) ether and other polyhydric alcohols and their derivatives, dimethyl (ethyl, butyl) ether and other ethers, diethyl phthalate, dimethyl phthalate and other esters, oleic acid, caprylic acid and other fatty acids, and n-dodecanol , Alcohols such as n-undecanol, and aliphatic hydrocarbons such as n-decane and n-dodecane.

In addition to the above components, various additives may be used in order to further optimize the physical properties and improve the properties. Examples thereof include viscosity modifiers, surface tension modifiers and antifungal agents.

The content of the compound represented by the general formula of Chemical formula 16 in the ink according to the embodiment of the present invention is 0.1 to 20% by weight, more preferably 0.5 to 1% by weight based on the total weight of the ink.
It is desirable to set it within the range of 0% by weight. When another oily dye is added, it is desirable to add 0.1 to 20% by weight of the compound represented by the general formula of Chemical formula 17.

[0051]

[Chemical 16]

(In the formula, R1 is O, S, Se, T
e, (- CH _{3) 2} of either, R2 is _{C n H 2n + 1 (n} = 1
4), R3 represents either CIO ₄ ⁻ or I ⁻ . )

[0053]

[Chemical 17]

(In the formula, R1 is O, S, Se, T
e, (- CH _{3) 2} of either, R2 is _{C n H 2n + 1 (n} = 1
4), R3 represents either CIO ₄ ⁻ or I ⁻ . ) The content of the organic solvent is 70 to 70% by weight based on the total weight of the ink.
It is within the range of 90% by weight.

Next, the basic structure of the recording head of the ink jet printer according to the embodiment of the present invention and the printer driving method will be described.

In FIGS. 1, 2 and 3, the pressure is applied to the ink using the electromechanical conversion means to eject and eject the ink as droplets from the nozzle holes of the recording head to form flying droplets. It is a figure which shows one Example of the 1st inkjet printer of this invention which records a dot image on top.

FIG. 1 is a plan view of the first substrate of the recording head,
2 is a cross-sectional view of the recording head during ejection of ink droplets, and FIG. 3 is a perspective view of the recording head. In each figure, the same numbers indicate the same things. Further, in FIG. 3, the number of nozzles is 5 for simplicity.

Reference numeral 10 denotes a first substrate, which is formed by molding plastic resin such as polysulfone or polycarbonate, glass, or ceramic by molding or laser processing, processing a glass plate by using a photolithography technique, or glass plate or metal. It is a photo-curable resin that is fused or adhered to a plate and processed and molded using photolithography technology. Reference numeral 11 is a nozzle hole, 13 is a pressure chamber, 15 is a common ink chamber, 12 and 14 are nozzle side and supply side ink flow paths, and the first substrate 10
It is formed by carving. Reference numeral 16 is an ink supply port.
The piezoelectric element 17 is adhered onto the second substrate at the position shown in the figure after the second substrate 18 is welded or adhered to the first substrate 10 to form an ink flow path. 20 is a flying ink drop,
Reference numeral 21 is a recording medium.

In the first ink jet printer driving method according to the present invention, the ink 19 supplied from the ink supply port 16 of the recording head formed by adhering or welding the first substrate 10 and the second substrate 18 is used. By applying a voltage to the piezoelectric element 17 adhered to the position facing the pressure chamber 13 of the second substrate 18 with the nozzle hole 11 filled, the piezoelectric element 17 bends and the pressure chamber 13 The volume is reduced and the ink droplets 20 are ejected and ejected and fly toward the recording medium 21.

In FIGS. 4, 5, and 6, thermal energy is applied to the ink to eject and eject as droplets from the nozzle holes of the recording head to form flying droplets, and a dot image is recorded on the recording medium. It is a figure which shows one Example of the 2nd inkjet printer of this invention which does.

FIG. 4 is a sectional view of the recording head during ejection of ink droplets, FIG. 5 is a sectional view taken along the line AB in FIG. 4, and FIG. 6 is a recording in which five thermal heads shown in FIGS. It is a perspective view of a head. In each figure, the same numbers indicate the same things.

The recording head is composed of a thermal head 41 used for heat-sensitive recording such as a facsimile and a substrate 40. The substrate 40 is formed by molding plastic resin, glass, or ceramic by molding or laser processing, processing a glass plate by photolithography technology, or photo-curing a photocurable resin that is fused or adhered to a glass plate or a metal plate. It is processed and shaped using technology. The thermal head 41 includes a protective film 42 formed of silicon oxide, silicon nitride, tantalum oxide, electrodes 43-1 and 43-2 formed of gold, copper, aluminum, tantalum-silicon oxide, or the like. The heating resistor 44 is made of polysilicon, the heat storage layer 45 made of glass or the like, and the substrate 46 having a good heat dissipation property such as alumina (aluminum oxide).

In the second method for driving an ink jet printer according to the present invention, the electrode 43 is provided in a state where the ink flow path of the recording head formed by adhering or welding the substrate 40 and the thermal head 41 is filled. -1,43
When an electric signal is applied to −2, a portion of the thermal head 41 indicated by n rapidly heats up, bubbles are generated in the ink 47 in contact there, and the ink is ejected and ejected by the pressure.
Ink droplets 49 are formed from the nozzle holes 48 and fly toward the recording medium 50.

An example of a printer using the recording head and ink will be described together with a comparative example, and the effect will be illustrated.

Example 1 The following components were mixed, sufficiently stirred to dissolve them, and then filtered using a membrane filter having a hole diameter of 0.8 μm to prepare an ink.

[0066]

Colorant: Compound of Chemical formula 18 5.0% by weight Solvent Black 3 15.0% by weight Solvent: Diethylene glycol diethyl ether 40.0% by weight Diethylene glycol dibutyl ether 40.0% by weight

[0067]

[Chemical 18]

This ink is supplied to a first ink jet printer using a recording head composed of a first substrate 10 and a second substrate 18, which are manufactured by molding and sintering zirconia, and ejecting ink droplets. Let The nozzle hole 11 of the recording head has a rectangular shape with a length of 40 μm and a height of 25 μm, the number of nozzle holes is 9, and the nozzle pitch is 35.
0 μm, the driving voltage of the piezoelectric element is 100 V at room temperature, and the frequency is 2 kHz.

FIG. 7 is a perspective view of the recording head during the ejection of ink droplets according to the first embodiment. From the ink supply port 16, the common ink chamber 15, the supply-side ink flow passage 14, the pressure chamber 13, and the nozzle-side ink flow passage. 12 and the nozzle hole 11 are filled with ink, and no bubbles enter. Therefore, printing can be performed without missing dots.

Under the above conditions, neutral PPC paper (made by Fuji Xerox), acid paper register paper (made by Daishowa Paper), 45 kg fine paper (made by Tojo Paper), recycled paper "Yamayuri" (honshu) The time until the ink was dried was visually observed to be 1 second or less. Further, the print density of the printed matter was measured with a densitometer (print contrast meter PCM-II, manufactured by Macbeth Co.).
When the reflectance of the printed dots was measured by inserting a filter having a visible light type sensitivity characteristic showing maximum absorption at about 550 nm into a densitometer, the reflectance was 8% on average, although it varied depending on the recording medium. .. If you calculate the print density from this,
The optical reflection density OD value is 1.1. When the OD value for the filter is 1.1, a sufficient blackness is felt even when visually observed.

When a filter having a near-infrared type sensitivity characteristic showing a maximum absorption at about 950 nm was inserted into a densitometer and the reflectance of the printed dots was measured, the variation due to the recording medium was averaged and the reflectance was 8%. Met. When the print density is calculated from this, the optical reflection density OD value is 1.1. When the OD value for the filter is 1.1, it can be sufficiently recognized by the optical character recognition scanning device and the bar code type scanning device described above.

Next, when this ink jet printer was left at room temperature and printing was carried out one week later, normal printing was possible. When the nozzle holes of the recording head of the printer were observed with a microscope, the nozzle holes were filled with ink, and no precipitation of solid content was observed.

Example 2 A glass layer 45 having a thickness of 5 μm was formed on an alumina substrate 46 by screen printing, and subsequently, TaSiO ₂ was used as a heating resistor 44 in a thickness of 1000 Å and gold electrodes 43-1 and 43. -2 as 30
After stacking to a thickness of 00 Å, a heating resistor pattern of 50 μm × 200 μm was formed by selective etching. Next, the SiO ₂ layer is sputtered 35
After the protective film 42 having a thickness of 00 angstrom is laminated to form the electric / thermal converter on the substrate to form the thermal head 41, the glass substrate 40 having an ink flow passage of 50 μm width × 50 μm depth is cut into the ink flow passage. And the heating resistor were joined together. Subsequently, the nozzle surface was polished so that the distance between the tip of the heating resistor and the nozzle hole surface 48 was 250 μm, and the recording head of the second inkjet printer was prepared. The ink of Example 1 was ejected using this recording head. As a driving condition of the recording head, a frequency of 5k
When it was driven at a frequency of 40 Hz, an applied voltage of 40 V, and an applied pulse width of 10 μsec, ejection was normally performed even after 100 million ejections of ink droplets were ejected. Disassemble this recording head,
When observing the thermal head portion with a microscope, adhesion of solids to the protective layer was not observed.

[Example 3] Under the same conditions as in Example 1, an ink having the following components was prepared.

[0075]

## EQU2 ## Colorant: Compound of Chemical formula 19 2.0% by weight Solvent Black 45 8.0% by weight Solvent: n-Pentadecane 90.0% by weight

[0076]

[Chemical 19]

A book using a recording head made of this ink, which is formed of a first substrate 10 having a glass plate in which ink flow paths are formed by a photolithography technique and a second substrate 18 made of a glass plate having a thickness of 0.3 mm. It was supplied to the first inkjet printer of the invention, and ink droplets were ejected and ejected. The nozzle hole 11 of the recording head has a rectangular shape with a length of 40 μm and a height of 25 μm, the number of nozzle holes is 24, the nozzle pitch is 140 μm, and the driving voltage of the piezoelectric element is 120 V at room temperature.
The frequency is 2.5 kHz.

Also in this embodiment, as shown in FIG. 7, no bubbles were found in the ink flow path during ink ejection. When printing was performed on the same recording medium as in Example 1 and the time until the ink dried was visually observed, it was about 1 second. Furthermore, when the printing density of the printed matter was measured with a densitometer, the reflectance when a filter having a visible light type sensitivity characteristic showing maximum absorption at about 550 nm was inserted into the densitometer was 15% on average for each recording medium. there were. When the print density is calculated from this, the optical reflection density OD value is 0.8. Further, the reflectance when a filter having a near-infrared type sensitivity characteristic showing maximum absorption at about 950 nm was inserted into the densitometer was 23% on average for each recording medium. When the print density is calculated from this, the optical reflection density OD value is 0.6. Even if the OD value for this filter is 0.6, it can be recognized by the optical character recognition scanning device or the barcode scanning device described above.

Next, when this ink jet printer was left at room temperature and printing was carried out one week later, normal printing was possible. When the nozzle holes of the recording head of the printer were observed with a microscope, the nozzle holes were filled with ink, and no precipitation of solid content was observed.

[Embodiment 4] Using the second ink jet printer used in Embodiment 2, Embodiment 3 described above is used.
Ink was ejected. The drive conditions of the recording head are the same as in the second embodiment. In this case as well, the ejection was normally performed even after the ejection ejection of 100 million times. Further, when the recording head was disassembled and the thermal head portion was observed with a microscope, no solid content was adhered to the protective layer.

[Comparative Example 1] The following components were mixed and an ink was prepared in the same manner as in the method described in JP-A-57-14660.

[0082]

## EQU00003 ## Sulfa black 1 1.0% by weight Direct black 163 3.25% by weight Sodium 2-pyridimethiol-1-oxide 0.1% by weight Tetrasodium ethylenediaminetetraacetate 0.2% by weight 2-hydroxyethyl-substituted polyethylene Imine 6.0% by weight Sodium carbonate 0.2% by weight Sodium bicarbonate 0.1% by weight Poroethylene glycol # 200 5.0% by weight N-methyl-2-pyrrolidone 4.0% by weight Ethylene glycol monobutyl ether 3.0 Wt% water 77.15 wt% This ink is ejected and ejected as droplets from the nozzle holes of the recording head by applying pressure to the ink by using an electromechanical conversion means to form flying droplets on the recording medium. Supply it to an inkjet printer that records a dot image on the The drop was allowed to discharge injection. The structure, configuration and driving conditions of the recording head are the same as in the first embodiment.

FIG. 8 is a perspective view of the recording head during ejection of the ink droplets of Comparative Example 1. 81 is a nozzle hole, 82 is a nozzle side flow path, 83 is a pressure chamber, 84 is a supply side ink flow path, 85 is a common ink chamber, 86 is an ink supply port,
The ink from the ink supply port 86 to the nozzle hole 81 is filled with ink. Further, 87 indicates bubbles. As described above, a large amount of bubbles 8 having a diameter of about 0.1 mm are provided in the common ink chamber 85, the supply-side ink flow passage 84, the pressure chamber 83, and the nozzle-side ink flow passage 82.
Infiltration of 7 is seen. Even if an attempt is made to reduce the volume of the pressure chamber 83 by applying a voltage to the piezoelectric element to bend the piezoelectric element in a state where there are bubbles in the pressure chamber 83, the volume of the volume reduction is absorbed by the bubbles, so that the ink is ejected. Not ejected and many missing dots occur during printing. This is because when the colorant Sulfa Black 1 is dissolved in water, it becomes very easy to foam.

[0084]

As described above, the present invention has the following excellent effects.

(1) Since the compound represented by the general formula of Chemical formula 20 has an excellent infrared absorption property and can be used in combination with other oil-based dyes, it is possible to obtain a high visual density by printing as an ink. Can be secured and 630nm
Optical character recognition device (OCR, which uses red or near infrared light emitting diode or semiconductor laser of ~ 940 nm)
OMR) and bar code type scanning devices can be sufficiently recognized and can be used as ink in printers for these devices. Such an effect can be applied to all kinds of paper including recycled paper.

[0086]

[Chemical 20]

(In the formula, R1 is O, S, Se, T
e, (- CH _{3) 2} of either, R2 is _{C n H 2n + 1 (n} = 1
4), R3 represents either CIO ₄ ⁻ or I ⁻ . (2) The compound represented by the general formula of Chemical formula 21 is stable against heat action and chemical change with plastics, glass, ceramics, rubber, etc. constituting the recording head and parts holding ink. Is. Therefore, the ink of the present invention is applied with thermal energy corresponding to the recording signal to the ink in the recording head, and this energy is ejected and ejected as a droplet from the nozzle hole of the recording head to form a flying droplet, which is then ejected onto the recording medium. Even when it is used in an ink jet printer for recording a dot image on a paper and repeatedly subjected to a thermal action, the ink does not undergo a chemical change, solids are deposited, or ejection failure is not caused. There is no chemical change with the material of the recording head or the parts that hold the ink during long-term use or during rest, so the solid deposition, the change in the physical properties of the ink, and the ejection failure that cause this do not occur. Does not occur.

[0088]

[Chemical 21]

(However, in the formula, R1 is O, S, Se, T
e, (- CH _{3) 2} of either, R2 is _{C n H 2n + 1 (n} = 1
4), R3 represents either CIO ₄ ⁻ or I ⁻ . (3) Polyhydric alcohols such as ethylene glycol, diethylene glycol, ethylene glycol monomethyl (ethyl, butyl) ether and derivatives thereof, and ethers such as dimethyl (ethyl, butyl) ether of the compound represented by the general formula of Chemical formula 22 , Esters such as diethyl phthalate and dimethyl phthalate, fatty acids such as oleic acid and caprylic acid, alcohols such as n-dodecanol and n-undecanol, and aliphatic hydrocarbons such as n-decane and n-dodecane Since the ink of the present invention has very good solubility in a solvent, thermal energy corresponding to a recording signal is applied to the ink in the recording head, and the energy is ejected and ejected as a droplet from a nozzle hole of the recording head. For inkjet printers that form flying droplets and record dot images on recording media Even in the case of use, the electromechanical conversion means is used to apply pressure to the ink to eject and eject as droplets from the nozzle holes of the recording head to form flying droplets, thereby forming a dot image on the recording medium. Even when used in an inkjet printer for recording, there is no precipitation of solids or adhesion of sticky substances in the nozzle hole, and no significant increase in the viscosity of the ink in the nozzle, and printing is performed normally even after a long recording pause. be able to.

[0090]

[Chemical formula 22]

(In the formula, R1 is O, S, Se, T
e, (- CH _{3) 2} of either, R2 is _{C n H 2n + 1 (n} = 1
4), R3 represents either CIO ₄ ⁻ or I ⁻ . (4) The compound represented by the general formula of Chemical formula 23 is extremely unlikely to cause foaming, and therefore, by applying pressure to the ink of the present invention by using an electromechanical conversion means, a droplet is ejected from the nozzle hole of the recording head. When used in an ink jet printer that forms jetted liquid droplets by ejecting and ejecting as a printhead to record a dot image on a recording medium, air bubbles in the ink flow path of the recording head may be generated under any driving conditions of the recording head and the printer. There is no occurrence.

[0092]

[Chemical formula 23]

(In the formula, R1 is O, S, Se, T
e, (- CH _{3) 2} of either, R2 is _{C n H 2n + 1 (n} = 1
4), R3 represents either CIO ₄ ⁻ or I ⁻ . (5) Further, according to the present invention, it is possible to secure ink storage stability, high ejection stability and ejection responsiveness, quick fixing of printed matter, and high printing quality, which are the necessary characteristics shared by inkjet printers. It also has the effect.

[Brief description of drawings]

FIG. 1 is a plan view of a first substrate of a recording head in a first inkjet printer according to an embodiment of the invention.

FIG. 2 is a sectional view of the recording head during ejection of ink droplets in the first inkjet printer according to the embodiment of the present invention.

FIG. 3 is a perspective view of a recording head in the first inkjet printer according to the embodiment of the invention.

FIG. 4 is a sectional view of the recording head during ejection of ink droplets in the second inkjet printer according to the embodiment of the present invention.

FIG. 5 is a sectional view of a recording head in the second inkjet printer according to the embodiment of the invention.

FIG. 6 is a perspective view of a recording head in the second inkjet printer according to the embodiment of the invention.

FIG. 7 is a perspective view of the recording head during ink droplet ejection in the first inkjet printer according to the embodiment of the present invention.

FIG. 8 is a perspective view of a recording head during ejection of ink droplets showing an example of a conventional technique.

[Explanation of symbols]

 10 First Substrate 11 Nozzle Hole 17 Piezoelectric Element 18 Second Substrate 20 Flying Ink Drop 21 Recording Medium 41 Thermal Head 48 Nozzle Hole 49 Flying Ink Drop 50 Recording Medium

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C09B 23/00 L 7375-4H M 7375-4H C09D 11/02 PTF 7415-4J

Claims (3)

[Claims] 1. An ink comprising a compound represented by the general formula of Chemical formula 1 as an ink material for forming a recorded image. [Chemical 1] (However, in the formula, R1 is O, S, Se, Te, (-C
H _{3) 2} of either, R2 is C _n H _{2n + 1} to (n = 1~4),
R3 represents either CIO ₄ ⁻ or I ⁻ . ) 2. An ink jet printer for recording a dot image on a recording medium by causing thermal energy to act on the ink and ejecting and ejecting it as a droplet from a nozzle hole of a recording head to record a dot image on a recording medium. Claim 1
An ink jet printer, characterized by using the described ink. 3. An ink jet for recording a dot image on a recording medium by applying pressure to the ink using an electromechanical conversion means to eject and eject as a droplet from a nozzle hole of a recording head to form a flying droplet. An inkjet printer, wherein the ink according to claim 1 is used as the ink.